user600942 - 6 months ago 22
Python Question

# Does sympy v1.0 factor give the wrong answer with (2*4) + (2*4)/(2 + x)?

Using python 3.5.1 64 bit on windows 8.1, I have installed sympy, 1.0.

Running interactively

``````from sympy import *
p = symbols('p')
factor('8 + 8/(2+p)')
``````

result is
`8*(p + 3)/(p + 2)`
.

If I go to http://live.sympy.org/ running sympy 0.7.6 and python 2.7.5 and enter the same equation and hit the evaluate button, I get the right answer.

``````8 + 8/(2+p)
``````

There is no reduction. Why am I getting the wrong answer with Python 3.5.1 and sympy 1.0?

You are not getting the wrong answer. All that `sympy.factor` ensures is that a polynomial is factored into irreducible fractions over the rationals.
So the form given by `factor` in version 1.0 is correct, and represents an irreducible fraction over the rationals.
Update : I ran your code on SymPy Live and you get the exact same fraction when using `factor`, without the 8 factored out. They are the same. Note as Steven Rumbalski said, that evaluating and factoring are two different things.